Abstract
In this work spectrally dependent optical parameters of nominally pure single crystals of yttrium aluminum garnet (YAG) and lutetium aluminum garnet (LuAG) were studied using spectroscopy ellipsometry together with transmittance measurements in a broad spectral range from 0.73 to 6.42 eV (193?1700 nm). Obtained data in terms of complex refractive index and reflectivity represent an extension of previous studies towards the ultraviolet spectral region and provide a background for the design of a variety of optical applications such as laser host matrix systems, doped luminescence materials, optical imaging devices for semiconductor immersion lithography, construction of scintillators and other devices operating in the ultraviolet spectral region.
A complete database of obtained optical parameters (real and imaginary parts of complex refractive index) in the whole spectral range is included in the supplementary part. Oxide-based transparent materials play a key role in various research and industry fields, which are focused on the construction of optical devices such as lasers, scintillators, telecommunications, etc.
For these applications is critical to know the exact optical parameters of used materials for all operational photon energies. Yttrium aluminum garnet Y3Al5O12 and lutetium aluminum garnet Lu3Al5O12 are important wide bandgap materials suitable for a wide range of optical applications such as laser host systems [1] or for optical lenses in semiconductor microlithography.
This is connected chiefly with their excellent mechanical stability, low thermal expansion coefficient, low-acoustic loss, a high threshold for optical damage, stability against chemical and mechanical changes, and excellent optical properties [2]. With its high density (6.73 g/cm3) and high effective atomic number of Zeff = 62 (compared to 30 in YAG) LuAG is also well-known as a material for scintillators [3] to detect high energy gamma or X-ray radiation.
High index of refraction, wide bandgap, broad optical transparency range from 190 nm to 5 ?m, and very low intrinsic birefringence [4] make